1. Field of Invention
The present invention relates to the field of multi-OS (Operating System) display technology, in particular to a control method for switching display between a plurality of OSs as well as a computer system.
2. Description of Prior Art
Multiple GOSs (Guest Operating Systems) can be concurrently running on one and the same hardware platform by using virtualization technology. The display content from the multiple GOSs can be outputted via one display card device to an external display apparatus for displaying, that is, the multiple GOSs can implement their own display, respectively, by sharing the same display card device.
The conventional technique in the virtualization domain is to let all of the GOSs use virtual display cards, while only one host OS uses the physical display card device. This method has disadvantages including very poor display performance for the GOSs and no support for many acceleration characteristics.
New techniques have been proposed so that the GOSs can use the physical display card device directly. But such techniques are enabled at the expense that only one of the GOSs can enjoy display output, while the rest cannot make any output via the display card.
To address the above problem, some techniques are gradually developed, with which all of the GOSs can use the physical display card device directly in certain manner like operating in series. These techniques can be specifically divided into two categories, one is separating display resources, e.g., display memory resources, among the GOSs by modifying device drivers, and the other is not separating display resources.
No matter which category of the above technique is adopted, displayed pictures may be distorted or blurred during the process of switching from one GOS to another. Even system collapse may happen sometimes.